Keysight Technologies InfiniiVision M9241A, Руководство программиста SCPI

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1356 Keysight InfiniiVision M9241/42/43A PXIe Oscilloscopes SCPI Programmer's Guide
38
Synchronizing Acquisitions
Example: Blocking and Polling Synchronization
# -*- coding: utf-8 -*-
# ********************************************************************
# This script using the Python language (http://www.python.org/) and
# the PyVISA package (http://pyvisa.readthedocs.org/) shows the two
# best synchronization methods for InfiniiVision oscilloscopes.
# Benefits and drawbacks of each method are described. No error
# handling is provided except in the actual synchronization methods.
# ********************************************************************
# Import modules
# --------------------------------------------------------------------
import sys
import visa
import time
# Initialization constants
# --------------------------------------------------------------------
# Get VISA address from Keysight IO Libraries Connection Expert
VISA_ADDRESS = \
"TCPIP0::a-mx4154a-60014.cos.is.keysight.com::inst0::INSTR"
GLOBAL_TOUT = 10000 # IO timeout in milliseconds
TIME_TO_TRIGGER = 10 # Time in seconds
# --------------------------------------------------------------------
# This is the time until the FIRST trigger event.
#
# While the script calculates a general timeout for the given setup,
# it cannot know when a trigger event will occur. Thus, you must
# still set this value.
#
# This time is in addition to the calculated minimum timeout... so, if
# an oscilloscope might take say, 1 us to arm and acquire data, the
# signal might take 100 seconds before it occurs... this accounts for
# that.
#
# The SCOPE_ACQUISITION_TIME_OUT calculation pads this by 1.1.
# --------------------------------------------------------------------
TIME_BETWEEN_TRIGGERS = 0.025 # Time in seconds - for Average,
# Segmented, and Equivalent Time modes, else set to 0
# --------------------------------------------------------------------
# In Average, Segmented, and Equivalent Time modes, the oscilloscope
# makes repeated acquisitions. This is similar to the above
# TIME_TO_TRIGGER, but it is the time BETWEEN triggers. For example,
# it might take 10 seconds for the first trigger event, and then they
# might start occurring regularly at say, 1 ms intervals. In that
# scenario, 15 seconds (a conservative number for 10s) would be good
# for TIME_TO_TRIGGER, and 2 ms (again conservative) would be good for
# TIME_BETWEEN_TRIGGERS.
#
# The default in this sample script is 0.025 seconds. This is to make
# the sample work for the LINE trigger used in this script when the